/Engine/Source/Runtime/MeshConversion/Public/DynamicMeshToMeshDescription.h
Update only attributes, assuming the mesh topology has not changed. Does not touch positions. NOTE: assumes the order of triangles in the MeshIn correspond to the ordering you'd get by iterating over triangles, on MeshOut This matches conversion currently used in MeshDescriptionToDynamicMesh.cpp, but if that changes we will need to change this function to match!
void UpdateAttributes ( const [FDynamicMesh3](API\Runtime\GeometryCore\DynamicMesh\FDynamicMesh3) * MeshIn, [FMeshDescription](API\Runtime\MeshDescription\FMeshDescription) & MeshOut, bool bUpdateNormals, bool bUpdateTangents, bool bUpdateUVs )